2.1 Kinetics of Nausea and Vomiting
Emesis is the final act of vomiting and may be described as the forceful expulsion of gastrointestinal contents through the mouth brought about by the descent of the diaphragm and powerful contractions of the abdominal muscles, triggered and coordinated by signals originating in the brain. Emesis is usually, but not always preceded by nausea and reteching. Nausea and vomiting may be caused by a number of stimulative factors including anesthetics, radiation, cancer chemotheraeutic agents, toxic agents, odors and psychological factors, reaction to various medicinals and motion sickness.